Tutorial for multiple robot arms with MoveIt

[Robotawi]

Description

The goal of this tutorial is to be a complete guide for ROS beginners to start by setting up the URDF model of the multiple arms to be able to plan motions for them. The steps are as follows.

1. Build the Xacro/URDF model of multiple arms.
2. Prepare the MoveIt config package using MoveIt setup Assistant (only points missing in the available tutorial).
3. Write the ros_control configuration for the multiple arms.
4. Integrate the simulation in Gazebo with MoveIt motion planning.
5. Plan arms motions with MoveIt Move Group Interface.

Progress

I followed the moveit_tutorials guideline and applied the flow of show to tell style. I used the Panda arm from FRANKA EMIKA for consistency with previous tutorials. I have already completed the first three steps of the tutorial. The fourth step is blocked by the provided official Panda hand model missing inertial elements, making it unready for Gazebo simulation. I could proceed with fixing the links missing the inertial elements, but this means another package than franka_description would be a dependency for the tutorial. **I wanted to ask my mentors, should it be done in this way? **

I am flexible in refining the content according to the need and preventing redundancy.

Checklist

• Required by CI: Code is auto formatted using clang-format.This tutorial does not contain C++ code yet..
• While waiting for someone to review your request, please consider reviewing another open pull request to support the maintainers

[welcome]

Thanks for helping in improving MoveIt and open source robotics!

[mamoll]

@AndyZe, can you have a look?

[jackcenter]

Should this be in the robot_description directory?

[Robotawi]

It does not have to, but I think this makes logical structure. Should I change it?

[Robotawi]

Truly thankful for the review, @jackcenter
I updated the tutorial based on your comments. Sorry about the delay.

I followed the tutorial from a beginner's perspective, revised every step, and fixed multiple issues. Luckily, the fix I made in the franka_description package to make util.xacro (contains inertia information) includable from other packages is now available in the binary installation. There is no need to ask users to install the package from the source. This was the reason behind the error you encountered. I updated the multiple arms xacro file to adapt to the change.

Hopefully, this tutorial will greatly help the community, including the users of the new simultaneous trajectory execution feature! Once it's done, I will port it to ROS 2.

Please review the tutorial one more time and let me know your suggestions, or if it's ready to be merged.

Thank you!

[AndyZe]

Thank you very much for your patience and diligence in pushing this forward!

I'm sorry to say, when I run build_locally.sh, I don't see your new tutorial in the webpage. I'm not sure why, yet.

Please disregard, that was an error on my end.

[AndyZe]

This looks like a very high-quality tutorial that explains a lot of concepts well!

It looks like the formatting of multiple_robot_arms.rst needs a bit of tweaking because too many bullet points show up when the webpage is built. You can build the webpage to test this with build_locally.sh if you did not know that already (in the root directory of this repo).

[AndyZe]

I believe you could delete CMakeLists.txt and package.xml from this PR since you instruct the user to catkin create pkg

[AndyZe]

Almost there! I think we can get this merged in the next few days.

[Robotawi]

It looks like the formatting of multiple_robot_arms.rst needs a bit of tweaking because too many bullet points show up when the webpage is built. You can build the webpage to test this with build_locally.sh if you did not know that already (in the root directory of this repo).

The formatting is fixed, and it looks good on the locally built webpage.

Thank you for pointing out this issue!

I removed the word MoveIt from the title for consistency. Here is what it looks like.

I think the tutorial is ready for the final review 🙂

[AndyZe]

This meets my quality standards now 👍 Thanks for going into such detail. I think this will help people put many concepts together.

I'll merge if we can just get CI passing now.

[welcome]

Congrats on getting your first MoveIt pull request merged and improving open source robotics!

[Robotawi]

This meets my quality standards now +1 Thanks for going into such detail. I think this will help people put many concepts together.

I'll merge if we can just get CI passing now.

Truly thankful for your time and comments, @AndyZe

I planned this tutorial to be the start of my contributions to MoveIt, and glad this step is done.